I used to think I just loved and only used GHS Boomers. For 20 years I only used one bass. Boomers felt and sounded great, plus they lasted longer than most other rounds I had tried. I started branching out with a couple new basses and stuck with Boomers without giving it too much thought. 5-6 years ago I got a second p bass type instrument and threw some boomers on, and didn’t love it. The stock DR Pure Blues sounded way better but I didn’t like the feel (being used to steel boomers). So I tried a pair of Chromes that I had liked on another p bass, but those weren’t blowing me away either (even well after the break-in period). I found some TI JF344 “accordion accessories” for $45 and took the plunge. Those strings brought that bass to life!!! My other p bass sounds it’s best with dead boomers, so those went back on and now I have a great p with flats and great p with rounds. I recently got a cheap squier and put Nordstrand preamp and Big Splits in. The stock strings were junk, and now I need to try out the DR, chromes, and boomers I have laying around, but will be open to trying other strings if none of those get me excited.
TL/DR = Now I let the bass decide.
Fender Am Std P - Old Boomers
Moollon P - TI Jazz flats
Warwick Fortress - La Bella Super Steps (or whatever stepwound strings I can find because that stupid bridge)
Squier modded with active Nordy’s - ?